available quantities of Corexit and increased production to supply the product to BP’s subsidiaries. On May 19, 2010 the EPA gave BP 24 hours to choose less toxic alternatives to Corexit, selected from the list of EPA-approved dispersants on the National Contingency Plan Product Schedule, and begin applying them within 72 hours of EPA approval of their choices; or, if BP could not find an alternative, to provide a report on the alternative dispersants investigated and reasons for their rejection. BP took the latter option, sending its report the next day. BP's response to dispersant alternatives was judged to be deficient by both the EPA and the US Coast Guard, requiring EPA to perform its own analysis on the relative toxicity of dispersants. Their peer-reviewed conclusions on August 2, 2010 found that Corexit 9500A was generally neither more nor less toxic than the other available dispersants, and that dispersant-oil mixtures were not generally more nor less toxic to test species than oil alone. On May 26, the EPA told BP to reduce the use of Corexit by 75%; surface use was prohibited unless a request for exemption in specific circumstances was granted, while subsurface use was capped at 15,000 gallons per day. After May 26 daily average use decreased 9%, an average of slightly more than 23,000 gallons per day. On July 15, 2010, BP announced that it had capped the leaking well, and the application of dispersants by the response effort ceased shortly thereafter. The total used in the event was 1.84 million gallons of Corexit EC9500A and Corexit EC9527A, with roughly 58% sprayed from the air. Composition Corexit 9527 At the beginning of the Gulf spill, the proprietary composition was not public, but the manufacturer's own safety data sheet identified the main components as 2-butoxyethanol and a proprietary organic sulfonate with a small concentration of propylene glycol. Warnings from the Hazardous Substance Fact Sheet for 2-butoxyethanol include: "Cancer Hazard: 2-Butoxy Ethanol may be a carcinogen in humans since it has been shown to cause liver cancer in animals. Many scientists believe there is no safe level of exposure to a carcinogen....Reproductive Hazard: 2-Butoxy Ethanol may damage the developing fetus. There is limited evidence that 2-Butoxy Ethanol may damage the male reproductive system (including decreasing the sperm count) in animals and may affect female fertility in animals". 2-butoxyethanol was identified as a causal agent in the health problems experienced